Forced to accept order under contract (8)
I believe the answer is:
Here is my best explanation:
'forced to accept order under contract' is the definition.
I can't judge whether this definition defines the answer.
'forced to accept order' is the wordplay.
'forced' becomes 'prised' (I've seen this before).
'to accept' is an insertion indicator.
'order' becomes 'om' (order of merit).
'prised' enclosing 'om' is 'PROMISED'.
(Other definitions for promised that I've seen before include "swore", "undertaken", "Gave one's word, pledged", "Undertook (to do something)", "Made a commitment to do" and "Betrothed".)